There exists the type of lamp unit for vehicles (for example, Patent 1, Patent 2, and Patent 3). The explanation of the existing lamp unit for vehicles is given now. The existing lamp unit for vehicles includes a reflector having an ellipse reflect surface, a semiconductor light source, for example LED and the like, arranged in such a way that its light emitting part is positioned at the first focus of the ellipse reflect surface, and a projection lens arranged on the reflector and projecting a predetermined distributed light pattern toward the predetermined direction.
The functions of the lamp unit for vehicles are now explained. The semiconductor light source, for example LED and the like, is lighted to emit light, and thus the light from the semiconductor light source, for example LED and the like, is reflected by the ellipse reflect surface, and, as a predetermined distributed light pattern, is projected (illuminates, emits, or is given off) outwardly in the predetermined direction from the projection lens.
However, because, in the existing lamp unit for vehicles, the light axis of the ellipse reflect surface and the light axis of the projection lens are horizontal, and the semiconductor light source, for example LED and the like, the reflector, and the projection lens are arranged in the horizontal direction, the depth dimension in the horizontal direction becomes big. Because of this reason, the existing lamp unit for vehicles can not meet the demands for reducing the depth dimension.
Furthermore, there exists the type of lamp unit for vehicles (for example, Patent 4) that uses a planar reflect surface and reduces the length between the front and the rear (i.e. reduce the depth dimension). However, this type of existing lamp unit for vehicles uses an electricity discharge lamp bulb instead of the semiconductor light source, for example LED and the like, as a light source. Moreover, in this type of lamp unit for vehicles, the light axis of the projection lens extends in the direction of the front and the rear (the horizontal direction) of the vehicle, making the light axis of the reflector intersect the light axis of the projection lens, and making the reflected light from the reflector reflected toward one side of the projection lens by the planar reflect surface. Therefore, because, in this type of lamp unit for vehicles, the electricity discharge lamp bulb, the reflector, the projection lens, and the planar reflect surface are arranged in the direction of the front and the rear of the vehicle, the depth dimension in the horizontal direction becomes big, just as the lamp unit for vehicles mentioned in Patents 1-3, and it can not meet the demands for reducing the depth dimension.
Moreover, there exists the type of lamp unit for vehicles (for example, Patent 5) in which the light axis of the first reflector intersects the light axis of the second reflector and they become a compact module. However, this type of existing lamp unit for vehicles is not the projector type of lamp unit for vehicles that does not use projection lens. And moreover, because this type of existing lamp unit for vehicles is the one in which the light axis of the first reflector intersects the light axis of the second reflector, the height dimension in the vertical direction increases at the same time the depth dimension in the horizontal direction reduces, and thus it can not meet the demands for reducing the depth dimension and the height dimension.
Furthermore, the existing lamp unit for vehicles mentioned above do not take into consideration the method of preventing the light, except the predetermined distributed light pattern projected from the projection lens, from emitting from the projection lens, and therefore, there exists the circumstance where the light except the predetermined distributed light pattern projected from the projection lens, i.e. the light not distributed, emits from the projection lens. In addition, the existing lamp unit for vehicles mentioned above do not take into consideration the method of the effective use of the light from semiconductor light source, and therefore, the existing lamp unit for vehicles mentioned above do not effectively use the light from semiconductor light source.
Patent 1: Publication No. 2006-107955
Patent 2: Publication No. 2005-302328
Patent 3: Publication No. 2004-311224
Patent 4: Publication No. 2005-228715
Patent 5: Publication No. 2004-207235